import changes from `dev' branch of rmottola/Arctic-Fox:

- Bug 1176414 - Clean up/rename various column index variables in nsTableRowFrame and nsTableFrame. r=dholbert (d8e33d549)
- Bug 1176105 - Remove the (largely gutted) nsTableIterator class, and replace with simple frame-list iteration. r=dholbert (46a15df19)
- Bug 1176555 - Replace explicit bit-twiddling of frame state flags by human-readable nsIFrame state-manipulation methods in table layout code. r=dholbert (aef9fb035)
- Bug 1176354 - Rename nsTableRowFrame::GetBSize to differentiate better from nsIFrame::BSize. r=dholbert (9b67203a0)
- Bug 1177600 - Properly adjust table row and cell positions when their containing block-size changes in vertical-rl writing mode. r=dholbert (413148d55)
- Bug 1177925: Use range-based for loops for nsFrameList iteration, in various places in layout. r=tn (6db450285)
- Bug 1148582 - Recycle mask layers attached to FrameMetrics. r=mattwoodrow (91360fbd8)
- Bug 1148582 - Apply async transforms to (ancestor) mask layers correctly. r=botond (d6fca66fb)
- Bug 1143575. Add some #includes to avoid unified-build issues on Windows. r=nical (ff78b76a3)
- Bug 1143575. Add some #includes to avoid more unified-build issues on Windows. r=nical (99e0548f4)
- Bug 1181832 - Keep gfxPrefs.h out of header files. r=kats (341f0aea0)
- Bug 1181832 - Include gfxPrefs.h from nsImageLoadingContet.cpp to fix bustage on a CLOSED TREE. r=bustage (d61a18ab9)
- Bug 1137557 - Part 0: TextEventDispatcher shouldn't forward keyboard events coming from TextInputProcessor to the parent process. r=smaug (87f70fcc4)
- Bug 1172405 - Fix build error when adding files to dom/workers and gfx/layers. r=nical (8e114b8bb)
- Bug 1061393 - Export display list info to layer scope viewer. r=kamidphish (60fd247f0)
- Bug 1072313 - Check for more leaks in the layers code. r=mstange (aacbb2e1c)
- Bug 1198979 - GC unused IPDL struct member. r=jmuizelaar (79c3113fb)
- add missing semicolon (17ba58b45)
- Bug 1153348 - Add an analysis to prohibit operator bools which aren't marked as either explicit or MOZ_IMPLICIT; r=jrmuizel (903dca970)
- Bug 1170388 - Restrict the static analysis error given about raw pointers to refcounted objects inside a lambda, to the case where the raw pointer is captured. r=ehsan (cbbd3174c)
- Bug 1180993 - Part 1: Add an analysis to help catch unused return values of specific types. r=ehsan (2420face4)
- Bug 1180993 - Part 2: Add the MOZ_MUST_USE attribute to mfbt, and use it to verify usage of already_AddRefed. r=ehsan (b72785a60)
- Bug 1123907 - Part 1: Add an analysis to ensure that a class marked MOZ_NEEDS_NO_VTABLE_TYPE cannot be instantiated by a class with a VTable; r=ehsan (0f5730c04)
- Bug 1123907 - Part 2: Add MOZ_NEEDS_NO_VTABLE_TYPE to Attributes.h, and use it to verify the EntryType argument of nsTHashtable; r=ehsan (2e80fc581)
- Bug 1159433 - Part 1: Add an analysis to ensure that some template arguments cannot be non-memmovable types; r=ehsan (3602e950f)
- uniform MOZ_MUST_USE, it will be renamed in patch 1267550 (3b5ebd4c5)
- add missing part of Bug 1187073 - Use MOZ_INHERIT_TYPE_ANNOTATIONS_FROM_TEMPLATE_ARGS to validate the usage of AlignedStorage2. r=ehsan (3b451bfb7)
- Bug 1159433 - Part 2: Add the MOZ_NON_MEMMOVABLE and MOZ_NEEDS_MEMMOVABLE_TYPE macros to MFBT; r=froydnj (171c23ec4)
- Bug 1159433 - Part 3: Make nsTArray_CopyChooser only accept memmovable argument types by default; r=froydnj (40cb4aa67)
- Bug 1159433 - Part 4: Mark nsTAutoString_CharT and nsAutoArrayBase as non-memmovable; r=froydnj (7dc6bd220)

layout/mathml/nsMathMLmtableFrame.cpp

@@ -772,9 +772,7 @@ nsMathMLmtableOuterFrame::GetRowFrameAt(nsPresContext* aPresContext,
     nsIFrame* rgFrame = tableFrame->GetFirstPrincipalChild();
     if (!rgFrame || rgFrame->GetType() != nsGkAtoms::tableRowGroupFrame)
       return nullptr;
-    nsTableIterator rowIter(*rgFrame);
-    nsIFrame* rowFrame = rowIter.First();
-    for ( ; rowFrame; rowFrame = rowIter.Next()) {
+    for (nsIFrame* rowFrame : rgFrame->PrincipalChildList()) {
       if (aRowIndex == 0) {
         DEBUG_VERIFY_THAT_FRAME_IS(rowFrame, TABLE_ROW);
         if (rowFrame->GetType() != nsGkAtoms::tableRowFrame)